In Barth Syndrome, elastic fibers replace muscle fibers --> endocardial fibroelastosis --> dilated cardiomyopathy at birth or shortly thereafter --> risk of cardiac arrhythmia and sudden death
"The natural history of BTHS cardiac disease has been described as 'undulating.' Both the character and severity of heart dysfunction can change significantly. The cardiomyopathy can evolve from dilated (thin) and/or hypertrophic (thick), or vice versa, and may or may not involve left ventricular noncompaction (LVNC), and sometimes hypertrabeculation. Furthermore, sometimes a patient sick enough to be awaiting a heart transplant can improve so dramatically as to be taken off the list, especially if the underlying metabolic abnormalities have been treated and improved. Unfortunately, the reverse also can happen, and heart function can deteriorate significantly, suddenly and unexpectedly, even during otherwise simple viral or bacterial infections. Life-threatening arrhythmias can occur, even when the heart function is in normal range. Vigilant cardiac monitoring is essential."
Text: https://www.barthsyndrome.org/barthsyndrome/
Image: (A) Example of a normal heart and a heart with left ventricular non-compaction (LVNC) and dilated cardiomyopathy. (B) Echocardiogram (apical 4-chamber view) of BTHS patient with same. (Jefferies, 2013, Wiley-Blackwell, John Wiley & Sons, USA). From Saric et al, Front. Genet., 19 January 2016.
